ブラウザの設定でJava Scriptの使用を有効にしてご利用ください。
出典:Wiktionary
From Middle English ther-to-fore, þeretofore, þer to-fore, þer toforn, þær toforen, from 古期英語 þǣr tōforan, equivalent to there + tofore.
theretofore